I think it just boils down to personal interest mostly, however I don't think Pinball will be as big in 20-years as it is right now. In fact, I think the reason pinball has seen a big resurgence in popularity recently is because you have three generational cohorts (Boomers, GenX, and Millennials) who are either in or have experienced their prime earning years and actually remember seeing pins regularly during their youth or young adulthood. So naturally we all want to own pins now which have become better than ever in certain ways, or just to own those cool DE, Sega, and B/W tables that we used to play during the 80s and 90s. Or if they can't own them, they go out to the many barcades that saturate nearly every big metro and keep these places afloat.
I'm sure some Zoomers (Gen Z) will take to pinball as they get older, but I feel like most probably won't since they either have no idea what it is or have such vague memories of seeing them in random places that it will mean very little to most of them. Most Zoomers never grew up with arcades and very few remember a time before the internet. Their lives have almost always revolved around their phones, apps, and console gaming. The idea of going to a business and paying per play on an arcade or pinball machine is something that appeals to few of them since they never had that growing up like older generations did.
I don't think pinball will ever die out completely, even after the last Millennial dies out in 100-years from now or whatever, but it will probably become a less popular hobby in a few years, and continue to decline as time goes on. Just my two cents, but I see almost no enthusiasm for pinball under the age of 25.